This invention relates to a pin-type synchronizer for a transmission. More specifically, this invention relates to an improved blocker and/or pre-energizer means for such a synchronizer.
Synchronizers of the general type disclosed herein are well known in the prior art as may be seen by reference to U.S. Pat. Nos. 5,339,936 and 4,018,319 and GB Patent 1,473,844, the disclosures of these patents are incorporated herein by reference. Synchronizers of the type disclosed herein generally include jaw clutches and blocker pins that extend axially from a friction member through first openings in a radially extending flange. The pins include angled blocker shoulders that engage angled blocker shoulders defined about the openings to prevent asynchronous engagement of the jaw clutches. These synchronizers may be of the double acting or the single acting as shown in the above-mentioned patents. Some of these synchronizers may include pre-energizers of the so-called split pin type in lieu of pre-energizers of the type in U.S. Pat. No. 5,092,439. Pairs of the split pins extend through second openings in the flange and interspaced between the first openings. Springs bias the pairs of split pins apart to ensure engagement of angled pre-energizer shoulders defined by the split pins and with angled pre-energizer shoulders defined about the second openings. The engaged shoulders effect engagement of the friction clutches in response to initial engaging movement of the shift flange.
In the event of wear of the angled shoulders defined about the first and/or second openings, the shift flange needs to be replaced to ensure proper operation of the blocking and/or pre-energizer functions. Further, when the same basic synchronizer is used in different positions in a transmission or in different transmissions, at may require different shoulder angles, whereby requiring a large inventory of shift flanges that differ only by shoulder angle.
An object of this invention is to provide improved blocker and/or pre-energized shoulders of a synchronizer.
Another object of this invention is to provide improved pre-energizer split pins for a synchronizer
According to a feature of this invention, a synchronizer is provided for a first drive secured against axial movement relative to a second drive having an axis about which the drives rotate. The synchronizer comprises: A first jaw means is rotatable with the second drive and is axially moveable into engagement with a second jaw means for positively connectively connecting the drives. A first friction means is axially moveable into engagement with a second friction means for synchronizing the drives. A radially extending flange is rotatable with the second drive. Blocker openings are circumferentially spaced apart and extending axially through the flange. Circumferentially spaced apart blocker pins are axially extending rigidly from the first friction means and a one of each pins is slidably received in an associated one of each of the blocker openings. Each blocker pin has a blocker shoulder engagable with a blocker shoulder disposed about the associated blocker opening for preventing asynchronous engagement of the first and second jaw means.
The improvement comprises blocker rings each having an inner circumferential portion defining one of the blocker openings and having an outer circumferential portion axially fixed in an inner circumferential portion of a flange opening extending axially through the flange.
According to another feature of the invention, a double acting synchronizer clutch includes: First and second axially movable friction means are rigidly connected together about a rotational axis in axially spaced relation on opposite sides of an axially movable, radially extending flange. A plurality of circumferentially spaced apart pre-energizer openings extend axially through the flange. A split pin assembly includes a pair of members biased apart by a spring assembly and extending axially through each pre-energizer opening and between the first and second friction means for effecting axial movement of the friction means in response to initial axial movement of the flange from a neutral position. Each pair of members defines a generally cylindrical outer surface with a radially outwardly open annular detent groove for receiving an inner circumferential portion of one of the pre-energizer openings.
The improvement comprises pre-energizer rings that each have an inner circumferential portion defining one of the per-energizer openings and an outer circumferential portion axially fixed in an inner circumferential portion of a flange opening extending axially through the flange.